Method of refining



March 24, 1931. R. c. OSTERSTROM ET AL 1,797,513

METHOD OF' REFINING Filed Feb. 2. 1928 x um tm@ 2WD ZOO Patented Mar. 24, 1931 UNITED STATES PATENT OFFICE RUDOLPH C. OSTERSTIROM, OF CHICAGO, ILLINOIS, AND ROBERT T. TUCKER, OF MUSKO- GEB, OKLAHOMA, ASSIGNORS TO THE PURE OIL COMPANY, OF CHICAGO, ILLINOIS, A

CORPORATION OF OHIO METHOD rOF BEFINING Application led February 2, 1928. Serial No. 261,315.

The present invention relates to improvements in methods of refining.

The invention is particularly ap licable to the refinin of cracked motor uels, that is-motor uels which have been manufactured as a result of cracking processes as said term is used in petroleum processes. Motor fuels or the like made in cracking operations containing a high proportion of unsaturated compounds and other compounds are present which on exposure to air polymerize to form tarry substances which are considered to be injurious to a lmotor. These tarry substances are known as s or resins. It is known that by subjectmg the vapors from a cracking unit to the action of fullers earth or similar substances, such compounds can be olymerized before the motor fuel or the li e goes to storage, the fullers earth probably acting as a catalyst to effect polymerization. The tarry substances so formed may be removed b redistillation, advantage being taken of their differences in boiling points. The motor fuel or the like is incidentally decolorized. It is to be noted, however, that though the fuel or the like is decolorized, it is not necessarily a fact that it has been entirely freed of gum'forming compounds.

The present invention relates to this gum removal effect, and an object of the present invention is to provide an improvement in eiciency in removing the compounds referred to and decolorizing the motor fuel, giving greater yield and an improved product per ton of treating medium.

A further object of the present invention is to provide a system for the treatment of cracked motor fuels and the like which is leiiicient in operation and which may be kept in service continuously for a relatively long period of time.

A further object is to provide an improved continuous process for treating cracked motor fuels.

A further object is to provide a process for refining cracked motor fuels which will produce better color and a more stable color than has been possible according to prior practice.

A further object is to lower the cost of refining cracked motor fuels.

A urther object is to provide a process and a system for carrying out said process which will be more eilcient than have been prior processes in removing gum forming compounds.

Further objects will appear as the description proceeds.

Referring tothe drawings- Figure 1 is a more or less dia ammatic view illustrating apparatus whic may be used in the practice of the present invention; an

Figure 2 is a view of a modification of part of the system shown in Figure 1.

Referring first to Fi re 1, the numeral 1 indicates a storage tan for the storage of cracked motor fuel or the like which is to be treated. The numeral 2 indicates an outlet pipe from the storage tank 1 leading to the regulating valve 3, which may be a manually operable valve. From the valve 3 a ipe `4 communicates with the pump 5, whlch is preferably a centrifugal pump. The outlet from the ump 5 is connected to the mixer 6,

which lea s to the bank of coils 7 in the heater or contactor 8. The mixer 6 may in many dicated by the numeral 9, whlch clay hopper has the outlet 10 controlled b the valve 11. The outlet 10 from the cla opper 9 communicates with the clay ceder 12, which takes the form of a tube 13 provided internally thereof with the screw conveyor 14. Sai screw conveyor 14 is driven by means of the variable speed motor 15, or by any other preferred driving means. The clay feeder 12 communicates at its outlet end with the pipe 4, which carries the fuel or the like from the storage tank 1, the clay feeder 12 being preferably arranged in angular relationship with the pipe 4. The clay feeder 12 will preferably have a downward slant from the outlet 10 to the pipe 4, whereby the effect of gravity may be made use of in deliverin clay7 to the fuel in the pipe 4. The term clay is used in its generic sense in this s ecifcation and is intended to refer genera y to reining agents, such for example as fullers earth, charcoal, bone ash, acid treated clays, bentonite, and other agents having the function of bleaching or decolorizing the fuel under treatment.

The contactor 8 is shown as being provided with a burner 16, which burner is intended to be illustrative of any type of means for communicating heat to said contactor 8. They outlet end of the bank of coils 7 communicates with the evaporator or fractionating tower 17 a pressure relief valve 18 being located in the pipe 19 leading from the bank of coils 7 to said evaporator 17. The evaporator 17 may be provided, in the upper portion thereof, with a plurality of bafies 20-20, which slant from the side edges of said evaporator 17 toward and past the vertical center line thereof, whereby said baflies are arranged in overlapping relationship. By reason of this overlapping relationship, any liquids or solids deposited upon said baiiles will take a tortuous path downwardly in the evaporator 17. The pipe 19 communicates with the evaporator 17 below the series of bailies 20-20. The lower region of the evaporator 17 may be provided with a heater. indicated generally by the numeral 21. Said heater 21 preferably comprises a series of vertically arranged tubes 22-22 arranged in parallel relationship with one another, whereby the tendency of solid matter to deposit upon said tubes will be minimized. Heating medium, such for example as superheated steam, may be conducted to and drawn from the tubes 22 through the pipes 23-23. The lower extremity of the evaporator 17 is provided with the draw-offl member 24 provided with the valve 25. `The up.- per" extremity of the evaporator 17 is provided withV the pipe 26 leading to the condenser 27. The outlet from the condenser 27 leads to the treated oil storage tank 28.

Figure 2 shows a slight modification of part of the system shown in Figure 1. According to the modification shown in Figure 2, the pipe 19 leading from the relief valve 18 communicates with the settler tank 29. The lower extremity of said settler tank is provided with the draw-0H member 30 provided with the valve 31. Connected with the upper extremity of the settler tank 29 is the outlet pipe 32, which leads to the treated oil storage tank 33.

a In practicing the present invention, fuel and refining agent may be continuously supplied through the pipe 4 and the clay feeder 12, respectively, said fuel and refining agent being forced by the pump 5 into the coils 7 in the contactor 8, said fuel and refining agent being intimately mixed either in the pump 5 or in the pump 5 and the mixer 6. The pressure maintained within the contactor 8 and the ressure maintained by the pump 5 will be e osen to suit conditions. It has been found that some gasolines vrespond to treatment at temperatures as low as 150 degrees F. at pressures as low as 40 pounds above atmospheric. Other gasolines will not respond until they are treated to temperatures as high as 500 degrees F. and with pressures varying from 40 pounds to 600 pounds per square inch. The man skilled in the art will understand, of course, that in order to get the best results he must vary the temperatures and pressures with changes in the oil to be treated and with changes in the nature of the refining agent. When the material is heated to relatively high temperatures, 1t 1s of course put into a condition where it will immediately vaporize upon being released into the evaporator 17 According to the system illustrated 1n Figure 1, the vaporized material is conducted to the evaporator or fractionating tower 17, the light fractions going overhead through the pipe 26 and condenser 27 and the treated oil storage tank 28, and the refining agent with entrained material dropping to the bottom of the tower, to be carried off continu'- ously. The valve 25 may be so controlled in practice as to maintain a liquid level above the heating tubes 22-22, insuring the continued treatment of the heavier fractions which condense withinthe tower 17 It may be desired in practice to cut down the temperature in the contactor 8, or to eliminate the firing of said contactor, subjecting the mixture of refining agent and fuel to pressure alone within the bank of coils 7 of the contactor 8. In this event, the pressure applied to the mixture within the contactor 8 will be chosen within the limits above referred to,

the exact pressure being readily determin able by one skilled in the art to suit the particular fuel being treated and the particular refining agent being used in order to get the desired results; The pressure obtaining in the contactor8 will be regulated by the pressure relief valve 18. The material under treatment will iiow through the pipe 19 into the settler tank 29 (Figure 2), the treated oil overflowing through the pipe 32 passing to the treated oil storage tank 33,' The refining agent and entrained matter can be withdrawn continuously from the settler tank 29 through the draw-off 30, which is controlled by the valve 31.

It will be understood that after the desired conditions as to temperature and pressure have been reached in the bank of tubes 7 in the contactor 8, the pressure relief valve 18 will be so regulated as to maintain these conditions while allowing the passage of treated material to the evaporator or fractionating tower 17. It will be understood that the fractionating tower illustrated is only one of a number of types of fractionating towers which may be used, others suitable for the plprpose being well known to those skilled in t e art.

As a result of the process above outlined, the product will be substantially free of gum forming compounds and will be materially decolorized. Moreover, the clayor other refining agent discharged will be substantially spent earth. In other words, the earth admitted into the system will be substantially completely utilized, permitting the use of a much smaller quantity of refining agentthan has been possible in methods in common use. The delays and expense incident to the changing of clay which has been objectionable in prior methods is minimized according to the present invention.

As indicated above, the pressure impressed upon the flowing mixture by the pump 5 may be as high as 600 pounds per square inch. Said pressure will be chosen to suit individual conditions, such for example as the neness of the refining agent, the viscosity of the liquid being treated, the temperature of the liquid being treated, and other conditions. The temperature within the coils 7 will be chosen to suit conditions, a temperature in the neighborhood of 350 degrees having been shown to be satisfactory in some instances. The teinperature may range from atmospheric ltemperature up to 500 degrees or evenhigher. The corelation of temperature and pressure Within the coils 7 will be such that the refining agent will be thoroughly impregnated, whereby to utilize the refining qualities to the greatest possible extent. The ordinary skilled worker inthe art may, of course, readily determine the proper temperatures and pres-.

sures to be used for the particular liquid under treatment, which, of course, depends upon the quality of the material to be treated and the treating medium to be used. The lower limit of pressure to be used will be the pressure necessary to impregnate `the particular refining agent with the particular liquid being treated at the temperature being used. Ordinarily it will be more economical to use the higher temperatures, inasmuch as the pressures necessary will be less at the higher temperatures than at the lower temperatures. With such agents and liquids as have come within the observation of applicants in their practice of the present invention, the minimum pressure to accomplish complete impregnation at the higher temperatures has been in the neighborhood of 60 pounds per sguare inch, though incomplete impregnation may be accomplished atless pressures.

I Many modifications of the present invention will occur to those skilled in the art. lt is intended'to cover all such modifications that fall within the scope of the appended claims.

What is claimed isl. A system for refining liquids comprising, means for mixing a liquid to be refined with an adsorbent, means for heating said mixture, pipe means connecting said mixing and heating means, a pump in said pipe means for placing the mixture underl pressure, a vaporizing and fractionating means adaptedA to receive said mixture from said heating means,

means for heating the lower portion of said last named means and a ressure relief valve between said first namedp heating means and said vaporizing and fractionating means.

2. A system for refining liquids comprising, means for adding an adsorbent to a flowing stream of liquid, means for conveying said constituents to a fiowing stream of o`il, subjecting the mixture to super-atmospheric pressure to impregna-te said adsorbent, then releasing the pressure and separating the treated oil in vapor form from the adsorbent and'constituents retained therein. g

4. The method of decolorizing and degumming cracked petroleum oils containing gumforming constituents in a high proportion of unsaturated compounds comprising, adding an adsorbent of the nature of fullers earth adaptd to assist in the removal of gum forming constituents to a flowing stream of oil, subjecting the flowing stream of said mixture adding an adsorbent of the nature of fullers earth capable of polymerizing gum forming to super-atmospheric temperature and pressure conditions, releasing' said super-atmospheric pressure, discharging the mixture into a vaporizing and fractionating zone and separately discharging treated oil vapors and adsorbent together with gummy `constituents from said zone. v

5. The method of decolorizing and degumming -cracked petroleum distillates containing gum-forming constituents and a high proportion of unsaturated compounds comprising, adding an adsorbent of the nature of fullers -earth adapted to assist in the removing of guru forming constituents to a flowing stream of oil, heating a flowing stream of said mixture at super-atmosplieric pressure, releasing the pressure and discharging the mixture into a fractionating zone to vaporize the major portion of ,the oil in said mixture.

6. The method of decolorizing and degumming cracked petroleum distillates containing gum-forming constituents comprising, adding a finely divided treating agent of the nature of fullers earth adapted to assist in the removal of gum forming constituents to a flowing stream of oil, heating a owing stream of said mixture at'super-atmospheric pressure to impregnate said treating agent, releasing the pressure, discharging the mixture into a fractionating zone and se-parately removing treated oil vapors andiI treating agent together with gummy constituents from said zone.

7. The method of decolorizing and degumming cracked petroleum distillates containing gum-forming constituents comprising, adding an adsorbent capable, of polymerizing gum forming constituents to a flowing stream of oil, subjecting the mixture to super-atmospheric temperature and pressure conditions to impregnate said adsorbent, releasing the pressure, discharging the mixture into a vaporizing and fractionating zone maintained at a temperature and pressure permitting the major portion of the oil in said mixture to be vaporized, heating unvaporized oils in said fractionating zone and separately removing treated oil vapors and adsorbent with constituents retained therein from said zone.

8. A method of decolorizing and deglnnming cracked petroleum distillates which contain a high proportion of unsaturated compounds and gum-forming constituents comprising, adding an adsorbent of the nature of fullers earth and capable of polymerizing gum-forming constituents to a flowtionating means, a vapor outlet from said fractionating means, and an outlet for spent adsorbent from said fractionating means.

Signed by RUDOLPH C. Os'rERs'rRoM at Chicago, Illinois, the 28th day of January, 1928, and by ROBERT T. TUCKER at Chicago, Illinois, the 28th day of- January, 1928.

RUDOLPH C. OSTERSTROM. ROBERT T. TUCKER.

ing stream of cracked distillate containing such gum-forming constituents, subjecting the mixture of distillate and adsorbent to an elevated temperature and to a super-atmospheric pressure to impregnate said adsorbent with the distillate gum-forming constituents and then reducing the pressure on said mixture to vaporize the treated distillate and separating said vaporized distillate from the adsorbent and gum-forming constituents retained in said adsorbent.

9. In an apparatus for refining cracked petroleum distillates, a conduit for cracked petroleum distillate, a mixer means ositioned in said conduit, means forv supp ying an adsorbent to said conduit, a pump positioned in said conduit between said adsorbent supply means and mixer means for subjecting the mixture of adsorbent and cracked distillate to pressure, a fractionating means, a conduit connecting said mixer means with said fractionating means, means forheating the mixture of cracked distillate and adsorbent in said conduit between said mixer means and fractionating means, and a pressure rellef valve in said conduit between said heatlng means and ractionating means.

10. In an apparatus for refining cracked petroleum distillates, a conduit for cracked petroleum distillate, a mixer means positioned in said conduit, means for supplying an adsorbent to said conduit, a pump posl- 

